Final answer:
The correct answer is option a. When multiplying 1.58 by 0.03, the product must be rounded to one significant figure, resulting in 0.05, which corresponds to option (a).
Step-by-step explanation:
In the context of significant figures, when multiplying two values such as 1.58 and 0.03, one must apply the rule that the product should be rounded to the same number of significant figures as the number with the fewest significant figures in the problem. In this case, 0.03 has only one significant figure.
Therefore, the product of 1.58 multiplied by 0.03 is 0.0474 which must be rounded to one significant figure. The number 0.0474 rounded to one significant figure is 0.05 since the next digit (4) does not require rounding up.
Thus, the correct choice in this instance is (a) 0.05.