Given the task definition and input, reply with output. You are given a short paragraph, a question and two choices to answer from. Choose the correct answer based on the paragraph and write the answer(not the key).

Paragraph: Plug-in hybrids run for a longer time on electricity and so are less polluting than regular hybrids.
 Question: Would a diesel powered submarine release less pollution if it were running on 
 Choices: A)its diesel engine 
B)its battery backup power?
its battery backup power?