I think it’s A! Sorry if I’m wrong
Explanation:
Big city contains different institutions, banks, hotels and airports. So people living in a big city have more opportunities of employment. Also, the international company take place in big city provides employment and good salary. So people living in a big city can find work easily and get high salary.
The infinitive phrase is "to spend the afternoon tobogganing".
An infinitive phrase expresses the action in a sentence. They can often function as nouns, adjectives or adverbs. E.g.: To win the approval of her mother-in-law by cooking dinner was Mary's only hope. The infinitive phrase in bold functions as a noun because is the subject of the sentence. When the phrase explains 'how' it functions as and adjective, when the phrase explains 'why' it functions as an adverb.
Can you clarify your question please