Answer: B. 0.4030 cm
Explanation:
When rounding up to significant figures, it is important to note that the zeros after a decimal counts as part of the significant figures given that it is preceded by a non-zero number. For example
0.2700 = 4 significant figures
Therefore, of all the options given; Only 0.4030 cm unambiguously contains four significant figures because the last zero is preceded by non-zero number, so, it will count making it a total of four significant figures.