Tinea is a skin infection caused by certain fungi. A significant fract

Para
A significant fraction of the people who contract tinea have outbreaks of its symptoms again and again because the original case of tinea was, in fact, never completely cured.
The para, in a way, claims that it was not a new infection in each case.

(A) can never be completely cured of tinea
There is a fraction of people who do not get it again. So this cannot be the basis of the reasoning.

(B) does not understand what causes tinea
Out of context

(C) did not get medical treatment for the original case of tinea
The assumption has to help fill up the gap between re-occurrence and not completely cured or between re-occurrence and new infection. It can be possible that the medical treatment did not result in complete removal of infection

(D) did 'not take steps to avoid contracting tinea
Out of context. We are not looking at the cause but relation between re-occurrence and new infection.

(E) has not been repeatedly infected with tinea
Correct. This tells us that these people were not infected with tinea again, but the re-occurence was the result of earlier infection

E