Answer:
C. option is the answer.
Step-by-step explanation:
First line print is straightforward. Second line introduces one blank (because of setw()) before alpha value output. Third line puts 3 blanks before beta value output.
123456789
△2463
△△△72
setw() function sets field width. It is part of the iomanip library. Default justification is left, i.e. spaces or blanks start from the left.
setw() can be inserted or extracted on input streams or output streams.