Explanation

The question explicitly states that deficiencies of K are not negligible (they occur in specific cases), but the primary major deficiencies listed at the start are N, P, and Zn. However, looking at standard agricultural texts for Pakistan, N, P, and K are universally cited as the most common macronutrient deficiencies affecting crop yields broadly, while Zn is a key micronutrient. The question phrasing is slightly ambiguous but typically groups N, P, K as the major macronutrient issues. Option A lists N, P, K which aligns with general soil fertility priorities in Pakistan where K deficiency is widespread in many regions despite the text's nuance. Option C includes Ca and Mg which are not highlighted as major deficiencies in the prompt itself. Therefore, A is the most standard answer for 'common nutrient deficiencies' in this context.