Long day plant among the following is

Answer: Option C

Long day plant among the following is cluster bean.
The plants which require more exposure to light are called long-day plants (LDP).
The cluster bean is a tropical plant. It requires a warm growing season. The crop requires 30 to 35°C temperatures at the sowing time for proper germination and 32 to 38°C temperature encourages good vegetative growth, but the high temperature at the flowering stage can result in premature flower drop. It can tolerate temperatures as high as 45 - 46°C. It is a photosensitive and indeterminate crop.