He tried to … the housemistress by entering the hostel through the back door.

Analyze the question: The sentence says he entered the hostel through the back door in order to avoid being seen by the housemistress. We need the word that means "to escape or avoid someone or something, often by cleverness or trickery."

Explain the concept: Let's check each option.

• A. reject: to refuse to accept someone or something. You can't "reject" a housemistress by sneaking through a back door. ✗
• B. repel: to drive back or push away, or to disgust. It implies force, which doesn't fit. ✗
• C. evade: to avoid or escape from someone or something, especially by cunning. ✓
• D. deflect: to turn aside something such as a ball, a blow, or criticism. You deflect an object or an attack, not a person. ✗

Solution: Entering through the back door is a way of dodging the housemistress so she doesn't catch him. That is exactly what evade means: "He tried to evade the housemistress."

Answer: The correct option is C. evade.

Tip: Think of evade as "escape by being sly." It is often followed by a person or duty, as in evade arrest, evade taxes, evade the teacher. Don't confuse it with invade (to enter by force). In exams, ask yourself what the person is really trying to do, and here he is trying to avoid being seen.