The error degree of freedom in Randomized Block Design (RBD) with ‘t’ treatments and ‘r’ replications is calculated by -

Correct option is A

· Correct answer: (a) r-1
· The error degree of freedom in Randomized Block Design (RBD) is calculated as r-1, where r is the number of replications.
Other options:
· (b) (r-1) (t-1): This is the formula for calculating the degree of freedom for the interaction term, not for the error.
· (c) t-1: This is the degree of freedom for treatments.
· (d) rt-1: This formula represents the total degree of freedom minus 1, which is not for the error.