The correct answer is 'b) Copeland'.

Copeland proposed the Four Kingdom system of classification in 1956. This system was a modification of the earlier Five Kingdom system proposed by Whittaker in 1969.

Explanation:

1. The Five Kingdom system:
- Whittaker proposed the Five Kingdom system of classification in 1969.
- According to this system, living organisms were classified into five kingdoms: Monera, Protista, Fungi, Plantae, and Animalia.
- The Monera kingdom included bacteria and blue-green algae, the Protista kingdom included unicellular eukaryotes, the Fungi kingdom included fungi, the Plantae kingdom included plants, and the Animalia kingdom included animals.

2. The Four Kingdom system:
- Copeland proposed the Four Kingdom system as a modification of the Five Kingdom system.
- According to this system, living organisms were classified into four kingdoms: Monera, Protista, Plantae, and Animalia.
- The Fungi kingdom was excluded from the classification, and fungi were included in the Plantae kingdom.

3. Justification for the Four Kingdom system:
- Copeland's Four Kingdom system was based on the concept of cellular organization.
- He classified organisms based on the presence or absence of a true nucleus and other cellular characteristics.
- According to Copeland, organisms with a true nucleus and well-defined cellular structures were placed in the Protista, Plantae, and Animalia kingdoms.
- Organisms without a true nucleus and with simpler cellular structures were placed in the Monera kingdom.
- Since fungi have a true nucleus and well-defined cellular structures, they were included in the Plantae kingdom.

4. Limitations of the Four Kingdom system:
- Although the Four Kingdom system provided a simplified classification, it had certain limitations.
- The exclusion of fungi from a separate kingdom led to a grouping of diverse organisms in the Plantae kingdom.
- This system did not adequately represent the evolutionary relationships among organisms.
- It also did not consider other important characteristics such as mode of nutrition and reproduction.

In conclusion, the Four Kingdom system of classification was proposed by Copeland as a modification of the earlier Five Kingdom system. Copeland's system classified organisms into four kingdoms: Monera, Protista, Plantae, and Animalia, with fungi included in the Plantae kingdom.

At first, microscopic organisms were classified within the animal and plant kingdoms. ... In 1938, Herbert F. Copeland proposed a four-kingdom classification, elevating the protist classes of bacteria (Monera) and blue-green algae (Phycochromacea) to phyla in the novel Kingdom Monera