Answer:
The type of underlined verbal in the given sentence is infinitive.
Step-by-step explanation:
Verbal are of three types: gerunds, infinitives, and participle. In the sentence, 'Zip lines are designed to create excitement for adventurous tourists', the underlined verbal 'to create' belong to the infinitive type of verbal.
An infinitive normally beings with the word 'to' and it acts as either noun, adverb, or adjective. For example: to jump, to sing, to dance and so on.
In the above mentioned sentence, the purpose of the verbal 'to create' is to express the motive behind designing zip lines, which is to create excitement.