Symptoms of which nutrient deficiency appear first on older leaves and then advance up the stem to younger leaves?

Correct option is A

The correct option is (a) Nitrogen Deficiency. Nitrogen deficiency typically shows up first in older leaves, causing yellowing, and the symptoms gradually advance toward younger leaves as the deficiency worsens.
(b) Phosphorus Deficiency – Affects younger leaves first.
(c) Potassium Deficiency – Affects the leaf margins
(d) Magnesium Deficiency – Magnesium deficiency in plants manifests as interveinal chlorosis (yellowing between veins)
(e) Calcium Deficiency – Affects new growth