A desires, a court to give judgment that he is entitled to certain land in the possession of B or basis of certain facts. Which 'B' denies to be true under section 101 of evidence Act?

As per Indian Evidence Act, 1872 S. 101. Burden of proof. –– Whoever desires any Court to give judgment as to any legal right or liability dependent on the existence of facts which he asserts, must prove that those facts exist. When a person is bound to prove the existence of any fact, it is said that the burden of proof lies on that person. In this question, A desires that judgment must be given in his favour in relation to land which is in possession of B, then he is the person who asserts it, therefore he must prove the existence of the relevant facts.