You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.

Most of the United States is a part of which tectonic plate?  
 (A) Pacific Plate (B) Eurasian Plate (C) North American Plate (D) South American Plate
C

Ella waves good-bye from the bus. What body system pulls on bones to let Ella wave her arm?  
 (A) muscular system (B) nervous system (C) digestive system (D) circulatory system
A

Algae are organisms that live in water. Scientists discovered a new type of red algae near Knight Island in Prince William Sound. Which statement is most likely a positive effect of this discovery?  
 (A) Scientists studying the red algae are disturbing local wildlife. (B) The red algae may help scientists better understand local food webs. (C) Visitors to Alaska may want to collect the red algae and take it home. (D) The red algae may be moved by boat to other areas when people travel.

B