Explanation

Blank (i): The phrase "such skills-based activities" later in the sentence directly refers back to skills-training sessions. This makes A. skills-training the best fit.

Blank (ii): The sentence says these sessions "does not ___ overall productivity; on the contrary..." The contrast indicates productivity is not harmed. Thus E. impair is correct.

Blank (iii): The phrase "on the contrary" introduces the opposite of impairment: participation increased productivity. Therefore G. elevated fits.

Putting the sentence together:

In a synthesis of over thirty controlled trials published in 2019, a team of occupational health researchers determined that allotting two afternoons per month to guided skills-training sessions within the corporate work schedule does not impair overall productivity; on the contrary, the data suggested that regular participation in such skills-based activities consistently elevated employee output, even as it reduced the total hours spent at the workstation.

Answer: A,E,G