1. The problem asks for the contrapositive of the conditional statement: "If a bird is an ostrich, then it cannot fly." 2. Recall the form of a conditional statement: If $P$, then $Q$. Its contrapositive is: If not $Q$, then not $P$. 3. Here, $P$ is "a bird is an ostrich" and $Q$ is "it cannot fly." 4. The negation of $Q$ is "it can fly." The negation of $P$ is "a bird is not an ostrich." 5. Therefore, the contrapositive is: If a bird can fly, then it is not an ostrich. 6. This matches the first option given. 7. The contrapositive is logically equivalent to the original statement, so it must be true if the original is true.