instruction:
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.
question:
Carlos was playing on a slide on a sunny summer day. Which property of the slide tells Carlos how much energy the slide absorbed from the Sun?  
 (A) the mass (B) the color (C) the height (D) the temperature
answer:
D


question:
To calculate the relative age of rocks, geologists use the rate of radioactive decay of isotopes present in their samples. What is the term used for the original amount of the elemental isotopes being investigated?   
 (A) rare earth isotopes (B) son isotopes (C) daughter isotopes (D) parent isotopes
answer:
D


question:
A scientist was observing a unicellular organism over a period of time. He noticed that vacuoles kept moving to the same place in the plasma membrane to empty their contents outside the cell. Which organism was he observing?  
 (A) amoeba (B) euglena (C) paramecium (D) volvox
answer:

C