Blackmann's Law of limiting factor

Q.

Who proposed the law of limiting factor?

Q. The law of limiting factors for photosynthesis was enunciated by

1. Robert Hill
2. Hans Adolf Krebs
3. Melvin Calvin
4. Frederick Blackman

Q. The law of limiting factors was proposed with particular reference to photosynthesis. Identify the scientist, who proposed this law?

1. Calvin
2. Weismann
3. Emerson
4. Blackman