The number 15.1 has three significant figures, encompassing the non-zero digits 1 and 5, as well as the trailing zero after the decimal point (option B).
What is a significant figure?
Significant figures include all non-zero digits and any zeros between them. In this case, "1" and "5" are non-zero digits, and the trailing zero after the decimal point is also considered significant.
In this case, The number 15.1 has three significant figures. Therefore, there are three significant figures in 15.1 (1, 5, and the trailing zero).
Note: The figure referred to here is not an image, rather, it is digits in mathematics.