(2) The following sentences are the opening sentences of a manuscript. Select the option with the correct choices of article (in the order of appearance) for the blanks: This study focuses on the stand-alone power operation in a house during __ blackout. The purpose of this type of operation, known as __ islanding, is to balance the power supply with load demand fluctuation and to ensure its long-term sustainability. *

A. a, the

B. a, no article needed

C. no article needed, an

D. no article needed, no article needed