To solve this problem you must apply the proccedure shown below:
1. As you can see in the figure attached, at the bottom of the stem and leaf plot you find the key, or the meaning of the information given, which is: 4|6=46 pounds.
2. Therefore, you have that digits actually are:
10,12,18,29,32,33,34,34,37,46,55,58,59
3. The greatest value is 59 pounds.
Therefore, the answer is the option B, which is: B. 59