26) D

The argument made by the passage is the sentence “More action is urgently needed…health and mortality.”

A neither strengthens nor weakens the argument, as it does not make a statement for or against breastfeeding.

B weakens that argument as it states that women in developing countries rely on bottle-feeding so it must be more beneficial than breastfeeding.

Although C states that commercial promotion of bottle-feeding is being limited by campaigns, it does not give a reason why breastfeeding is beneficial. So it does not directly strengthen the argument.

D states that breastfeeding is good for the mother and the child. Therefore, it strengthens the argument because it gives and additional reason why breastfeeding is beneficial. (It is good for the mother as well).

So D is the answer.