Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 35 to 42.

In the North American colonies, red ware, a simple pottery fired at low temperatures, and stone ware, a strong, impervious grey pottery fired at high temperatures, were produced from two different native clays. These kinds of pottery were produced to supplement imported European pottery. When the American Revolution (1775-1783) interrupted the flow of the superior European ware, there was incentive for American potters to replace the imports with comparable domestic goods. Stoneware, which had been simple utilitarian kitchenware, grew increasingly ornate throughout the nineteenth century, and in addition to the earlier scratched and drawn designs, threedimensional molded relief decoration became popular. Representational motifs largely replaced the earlier abstract decorations. Birds and flowers were particularly evident, but other subjects---lions, flags, and clipper ships---are found. Some figurines, mainly of dogs and lions, were made in this medium. Sometimes a name, usually that of the potter, was die-stamped onto a piece.

As more and more large kilns were built to create the high-fired stoneware, experiments revealed that the same clay used to produce low-fired red ware could produce a stronger, paler pottery if fired at a hotter temperature. The result was yellow ware, used largely for serviceable items; but a further development was Rockingham ware---one of the most important American ceramics of the nineteenth century. (The name of the ware was probably derived from its resemblance to English brown-glazed earthenware made in South Yorkshire.) It was created by adding a brown glaze to the fired clay, usually giving the finished product a mottled appearance. Various methods of spattering or sponging the glaze onto the ware account for the extremely wide variations in color and add to the interest of collecting Rockingham. An advanced form of Rockingham was flint enamel, created by dusting metallic powders onto the Rockingham glaze to produce brilliant varicolored streaks.

Articles for nearly every household activity and ornament could be bought in Rockingham ware: dishes and bowls, of course; also bedpans, foot warmers, cuspidors, lamp bases, doorknobs, molds, picture frames, even curtain tiebacks. All these items are highly collectible today and are eagerly sought. A few Rockingham specialties command particular affection among collectors and correspondingly high prices.

Which of the following kinds of Rockingham ware were probably produced in the greatest quantity?

They have _________ a lot of extensive research into renewable energy sources.