To determine the appropriate unit conversion for calculating the time it takes for a ladybug to crawl up a 10-foot section of a wall, we need to convert the distance from feet to inches because the ladybug's speed is given in inches per second.
1 foot is equal to 12 inches, so to convert 10 feet to inches, we multiply:
\[ 10 \text{ feet} \times \frac{12 \text{ inches}}{1 \text{ foot}} \]
This means the correct choice is:
A. Converting feet to inches by multiplying 10 feet by 12 inches over 1 foot.
This will give you the distance in inches needed to then calculate the time it takes to crawl that distance at a speed of 3 inches per second.