In a situation when MRSxy > Px / Py, the consumer would react by:

Option 1 -> When MRSxy > Px/Py, the consumer values Good X relatively more than its market price suggests, so decreasing X consumption would be irrational.

Option 2 -> Since the consumer is willing to give up more Y for X than the market requires, increasing Y consumption moves away from equilibrium.

Option 3 -> The consumer values Good X more highly relative to Good Y compared to their price ratio, making X relatively cheaper. The rational response is to increase X consumption.

Option 4 -> While Y consumption may decrease as a consequence, this is not the primary action the consumer takes to reach equilibrium.

Hence, Option 3: Increasing the consumption of Good X -> When MRSxy > Px/Py, it means the consumer's willingness to sacrifice Good Y for an additional unit of Good X exceeds the market's price ratio. In other words, Good X is relatively undervalued compared to the consumer's preference. To maximize utility and reach equilibrium (where MRSxy = Px/Py), the consumer will increase consumption of Good X. As X consumption increases, MRSxy decreases due to diminishing marginal rate of substitution, eventually reaching equilibrium. -> correct