Which of the following types of light are strongly absorbed by plants?

Plants absorb light most effectively in the blue and red regions of the visible spectrum because chlorophyll pigments capture photons at those wavelengths. Textbook summary states that out of the seven visible colours, only red and blue are effective for photosynthesis, with plants responding differently to blue versus red light [1]. Chlorophyll a shows strong absorption peaks in the blue (~430 nm) and red (~662 nm) regions, and chlorophyll b has similar blue and red peaks, making blue and red the primary drivers of photosynthetic absorption. Reviews of photosynthetic systems also note that chlorophylls absorb mainly red and blue wavelengths while reflecting/transmitting green, which is why leaves appear green [2].

Sources

1. [1] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 13: Plant Diversity of India > 13.2.1. Fntensity of light on growth of plants > p. 197
2. [2] https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/photosystem