The team has suggested a number of studies to be ______________ before the scheme is actually put through.

Correct option is A

The correct word for the given blank is ‘undertaken’
(a) undertaken means to do or begin to do something
(b)dumped means deposit or dispose of (rubbish, waste, or unwanted material), typically in a careless or hurried way.
(c)unified means make or become united, uniform, or whole
(d)supervened means occur as an interruption or change to an existing situation.
(e)disregard means pay no attention to; ignore.