The Indian Ocean Trade network connected Asia, Africa, and Europe. Salt, gold, slaves, iron, and ivory were exported from Africa, and silk, porcelain, spices, and cloth were exported from Asia. Very little was exported from Europe. How did this affect European exploration?

A. European nations searched westward for new lands with the resources that Europeans could use to trade internationally.

B. European nations searched westward for new markets in which to sell their goods because Africans and Asians did not buy them.

C. European nations delayed exploration because large sea faring vessels were being used in the Indian Ocean Trade network.

D. European nations delayed exploration because they were getting the goods they needed from Asia and Africa.

The authors of the paper "fudging the numbers: distributing chocolate influences student evaluations of an undergraduate course"† carried out a study to see if events unrelated to an undergraduate course could affect student evaluations. students enrolled in statistics courses taught by the same instructor participated in the study. all students attended the same lectures and one of six discussion sections that met once a week. at the end of the course, the researchers chose three of the discussion sections to be the "chocolate group." students in these three sections were offered chocolate prior to having them fill out course evaluations. students in the other three sections were not offered chocolate. the researchers concluded that "overall, students offered chocolate gave more positive evaluations than students not offered chocolate." indicate whether the study is an observational study or an experiment. give a brief explanation for your choice.