The domestic sewage in large cities :

Consider the following four statements (a-d) and select the option which includes all the correct ones only :
(a) Single cell Spirulina can produce large quantities of food rich in protein, minerals, vitamins etc.
(b) Body weight-wise the microorganisms Methylophilus methylotrophus may be able to produce several times more proteins than the cow per day
(c) Common button mushrooms are a very rich source of vitamin C
(d) A rice variety has been developed which is very rich in calcium

Read the following four statements (A-D) :
(A) In transcription, adenosine pairs with uracil
(B) Regulation of lac operon by repressor is referred to as positive regulation
(C) The human genome has approximately 50,000 genes
(D) Haemophilia is a sex-linked recessive disease
How many of the above statements are right ?

In gobar gas, the maximum amount is that of :