Answer: visite
Deseo que Marta visite los museos de arte en España porque son magníficos.
I wish Marta to visit art museums in Spain because they are magnificent.
Step-by-step explanation:
The main verb in this sentence is in indicative mode, that is used to express reality: "Yo deseo", I will. The subordinate clause works as the direct object of the main verb and contains a change of subject from the main clause to the subordinate clause. The subjunctive mode is used: "que Marta visite".
