Concept:After the verb "wish", use the simple past tense to talk about an unreal present desire.
Explanation:The verb "begin" has the forms "begin", "began", and "begun".
The phrase "now wishes" shows that Ben's feeling is in the present.
When we use "wish" about the present, we follow it with the simple past tense.
So the correct choice is "began".
"Begun" needs a helping verb like "has" or "had", so it is not correct here.
"Begins" and "has begun" do not match the pattern of "wish + simple past".
Answer:A. began