Answer: a nanometer is one billionth of a meter
0.000000001 m or 
Answer: The third answer
Explanation: Not exactly sure how to word this but all I can say is basically proper punctuation and capitalization is used in that answer. The sentence is correctly begun with a capital letter and the comma is used correctly. All of the other answer options do not fit and wouldn’t be correct.
Answer B "I have been seeking work,and I would appreciate this opportuinty."