Zizyphus mauritiana is:

Correct option is B

Zizyphus mauritiana, commonly known as Indian jujube or ber, is a tetraploid species.
Key Points:
· Tetraploid organisms have four complete sets of chromosomes (4n).
· In Zizyphus mauritiana:
· The chromosome number is 2n = 4x = 48.
· Here, "4x" signifies its tetraploid nature.
· Polyploidy (having more than two sets of chromosomes) in plants often results in:
· Increased vigor and better adaptability.
· Larger fruit size and greater tolerance to drought and poor soils.
· This polyploidy is one of the reasons why ber (Zizyphus mauritiana) thrives even under semi-arid and adverse conditions.
Other Options Explained:
· (a) Diploid: A diploid would have two sets of chromosomes (2x), but Z. mauritiana is tetraploid.
· (c) Hexaploid: Having six sets of chromosomes, not applicable here.
· (d) Octaploid: Eight sets of chromosomes, not the case for ber.