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.

[Q]: One hot summer, a grassland experienced a drought. Which most likely happened in the ecosystem during this time?  
 (A) The competition for food among primary consumers increased. (B) Nutrients cycled through the system at a faster rate. (C) Less solar radiation was able to enter the system. (D) Secondary consumers became extinct.
[A]: A


[Q]: Florida has a large supply of phosphate that ancient seas deposited millions of years ago. The phosphate contains the remains of animals that were deposited in layers on the sea floor. Which type of rock did the phosphate become?  
 (A) intrusive igneous (B) extrusive igneous (C) clastic sedimentary (D) organic sedimentary
[A]: D


[Q]: Earthquakes are vibrations of Earth's crust. What device is used to measure the size of an earthquake?  
 (A) barometer (B) Doppler radar (C) depth scale (D) seismograph
[A]:
D