The chlorophyll pigment present in Volvox are

The correct option is both (a) and (b).

Volvox is a genus of freshwater green algae that belongs to the division Chlorophyta.
Green algae (chlorophytes) are characterized by having photosynthetic pigments that are very similar to those found in land plants.

The primary photosynthetic pigments present in green algae like Volvox are:
1. Chlorophyll a: This is the primary photosynthetic pigment present in all oxygenic photosynthetic organisms. It absorbs light energy mainly from the blue-violet and red wavelengths.
2. Chlorophyll b: This is an accessory pigment that helps in collecting light energy and passing it on to chlorophyll a. It absorbs light energy primarily from the blue and red-orange wavelengths.

Because Volvox contains both chlorophyll a and chlorophyll b to capture light energy for photosynthesis, the correct answer is indeed both (a) and (b).