This question is based on the play “On the Face of It” by Susan Hill. The play highlights the emotional and psychological struggles of two physically challenged characters.
Step 1: Understand the characters.
Derry has a burnt face due to an accident with acid, which makes him self-conscious and isolated. Mr. Lamb has lost one of his legs in the war and walks with the help of a tin leg.
Step 2: Analyze the options.
(A) Vision impairment: Neither of them suffers from vision problems.
(B) War: Although Mr. Lamb lost his leg in war, both characters are primarily victims of physical disability.
(C) Physical impairment: This is correct because both Derry and Mr. Lamb suffer from physical disabilities.
(D) None of these: Since option (C) is correct, this option is incorrect.
Step 3: Conclusion.
Both Derry and Mr. Lamb are victims of physical impairment, which affects their lives and attitudes. Hence, the correct answer is (C).
Final Answer:
\[
\boxed{(C) \, \text{Physical impairment}}
\]