Which measurement has the greatest number of significant figures?

A.) 6.060 mg

B.) 60.6 mg

C.) 606 mg

D.) 60600 mg

Significant figures has few rules: non zero numbers are significant; trailing zeros are significant; zeros between nonzeros are significant. Hence, in this case, we can see that A has 4 sig figs, B has 3 sig figs and D has 3 sig figs too. answer is A