In 1969, whittaker proposed moving the from the kingdom plantae to a separate kingdom due to structural and metabolic differences.

Fungi

Explanation:

Prior to the work of R. H. Whittaker in 1969, scientists classified fungi  under the plant kingdom because they possessed characteristics similar to that of plants, such as they lacked ingestible food materials, they grew from the soil, and they posses a cell wall and they are immobile.

But in 1969, a five kingdom classification (Monera, Animalia, Plantae, Protista and Fungi) was proposed by Whittaker and it was therefore suggested that fungi be moved from the kingdom Plantae and be given a separate kingdom, Fungi. This was due to differences in the structure and metabolism, such the fact that fungi are not photosynthetic.

the answer would be d