Final answer:
The correct form of the verb in the blank is 'tuvo'
Step-by-step explanation:
The correct answer is A. tuvo. The verb form for 'designer' (diseñador) in the past tense is 'tuvo' which means 'had'. 'Tuve' and 'tenemos' are incorrect forms of the verb 'tener' (to have) which do not match with the subject 'diseñador'. 'Tiene' is the present tense form of 'tener' which is also incorrect for this sentence.
Learn more about Spanish verb conjugation