Step 1: Parse the counterfactual.
"\emph{Even if I had known} ..., I \emph{would not have} gone ..." is a counterfactual construction. It contrasts the \emph{actual} situation with a hypothetical one.
Step 2: Infer the actual situation.
By using the counterfactual "had known," Ramya implies that \emph{in reality she did not know}. The sentence discusses what her action would have been \emph{even under the alternative} where she knew.
Step 3: Eliminate distractors.
(A) claims she knew – contradicts the counterfactual implication.
(C) and (D) add information (friendship status, leg injury) not entailed by the statement.
\[
\boxed{\text{Ramya did not know Josephine was in the hospital.}}
\]