Regarding the identification of plants and animals, keys are prepared on the basis of similarity and dissimilarity of characters. Which of the following are correct about keys?
A. Contrasting characters generally occur in a pair called a couplet
B. A choice made between two similar options resulting in accepting of only one and rejecting the other
C. Each statement in the key is known as a lead
D. Keys are generally analytic in nature
E. Key is the collection of plants
Choose the correct answer from the options given below
1. A and B only
2. B and E only
3. B and D only
4. A, C and D only