Alpine plants which are commonly found at higher altitudes exhibit _____.

The correct option is A Xerophytism
In Alpine region, water is permanently frozen all round the year. Hence, plants will not get liquid water for their physiological needs. Effectively, it means xerophytic conditions and hence plants show xerophytic adaptations like sunken stomata, reduced needle like leaves etc to conserve water.

So, the correct answer is 'Xerophytism'