Which of the following have same number of significant figures?
(A) 0.00253
(B) 1.0003
(C) 15.0
(D) 163
Choose the correct answer from the options given below

Let us count the significant figures in each number:

(A) 0.00253: Leading zeros are not significant. So significant figures = 2, 5, 3 = 3 significant figures.

(B) 1.0003: All digits are significant (zeros between non-zero digits are significant). So significant figures = 1, 0, 0, 0, 3 = 5 significant figures.

(C) 15.0: The trailing zero after the decimal point is significant. So significant figures = 1, 5, 0 = 3 significant figures.

(D) 163: All non-zero digits are significant. So significant figures = 1, 6, 3 = 3 significant figures.

A, C, and D all have 3 significant figures.

The correct answer is Option 4: A, C and D only.