Choice A Reason:
 Informing the client of the adverse effect of diarrhea is less common with clonidine use, especially in comparison to other side effects like dry mouth or skin irritation.
Choice B Reason:
 Monitoring for weight loss isn't a primary concern specifically associated with transdermal clonidine use.
Choice C Reason:
 Advising the client about increased dry mouth is appropriate. Dry mouth is a common side effect of clonidine, especially when it's administered transdermally (via a patch). Informing the client about this potential side effect helps them anticipate and manage it. Other side effects might include skin irritation or redness at the patch application site, but increased hypopigmentation under the patch is not a recognized or typical side effect of transdermal clonidine.
Choice D Reason:
Checking for increased hypopigmentation under the patch is not a recognized effect of transdermal clonidine.