The respective number of significant figures for the numbers 23.023, 0.0003 and 2.1×10-3 are

Q. The respective number of significant figures for the numbers 23.023, 0.0003 and 2.1×10-3 are

1. 5, 1, 2
2. 5, 1, 5
3. 5, 5, 2
4. 4, 4, 2

Answer: 5, 1, 2