Choose the correct form of the verb. Rudolph ___ a red nose.

The sentence describes a permanent characteristic of Rudolph. The verb 'has' is used to indicate possession or a characteristic in the present simple tense. 'Is having' would imply a temporary state, which is not appropriate for describing a physical attribute like a red nose. 'Have' is incorrect because the subject 'Rudolph' is third-person singular, requiring 'has'. Therefore, the correct form is 'has'.

Rudolph has a red nose.