In a later lesson we are given 'sự lựa chọn' as the noun version of 'lựa chọn'. So is 'lựa chọn' the verb/adjective or it can be used as a noun also?
This can function as both a noun and a verb in this case. Adding in "sự" makes it definitely a noun, but it's not always required.
Which is the right option.