Used to introduce the single most important benefit of the option you are supporting.
“The main advantage is that this plan includes unlimited data, which we really need.”
“The main advantage is the shorter commute, which would save us hours every week.”
In Task 5, clearly identifying your top reason helps organize your response and gives the examiner an easy signpost to follow your logic. Use this phrase right after stating your choice, then follow it with one strong, specific benefit rather than a vague statement.
Synonyms: the biggest benefit is, the key advantage is, what stands out most is