Yes, you are correct. The correct answer is C. "Recuerdo que era tímido." The blank space should be filled with a verb that describes remembering or recalling, and "recuerdo" is the only option that fits. The verb "lloro" means "I cry," "molesto" means "annoyed," and "me porto" means "I behave." Only "recuerdo" matches the intended meaning in this context.
