Calcium is essential for cell wall development and root growth, but its deficiency tends to manifest differently than yellow leaves. Yellow leaves in a young plant are often a symptom of nutrient deficiencies. However, calcium deficiency typically causes different symptoms, such as:

- Tip burn or necrosis (death of cells) on young leaves

- Distorted or curled leaves

- Weakened stem and root growth

In contrast, deficiencies in the other options can cause yellow leaves:

B. Magnesium deficiency: Interveinal chlorosis (yellowing between veins)

C. Potassium deficiency: General yellowing or scorching of leaves

D. Boron deficiency: Yellowing or chlorosis of leaves, especially in young plants