Explanation:

Oppression- prolonged cruel or unjust treatment or exercise of authority. Depreciation means a reduction in the value of an asset over time, due in particular to wear and tear.

Surge means increase suddenly and powerfully. Thus, it is the antonym of the given word.

Devaluation means the reduction or underestimation of the worth or importance of something.

Slump means undergo a sudden severe or prolonged fall in price, value, or amount.