According to the passage, scientists examine the genomes of astronauts in order toA．select

According to the passage, scientists examine the genomes of astronauts in order to

A．select suitable astronauts for the space flight.

B．design countermeasures against gene mutation.

C．detect and cure the deficiencies in their genes.

D．prepare personalized gene-based medicine.

请帮忙给出正确答案和分析，谢谢！