The correct answer is (a) Section 91.
Section 91 of the Indian Evidence Act deals with presumption as to powers of attorney. It states that “where a person is shown to have acted in a particular way, and there is evidence that he acted under the authority of a power of attorney, the court may presume that he had such authority, unless the contrary is proved.”
This section is based on the principle of estoppel, which means that a person is estopped from denying the truth of a statement that they have made or that has been made on their behalf. In this case, the person who has acted in a particular way is estopped from denying that they had the authority to do so, unless they can prove that they did not have such authority.
Section 91 is a useful provision because it can help to resolve disputes about whether or not a person had the authority to act on behalf of another person. It can also help to protect people who have acted in good faith, believing that they had the authority to do so.
The other options are incorrect because they do not deal with presumption as to powers of attorney. Section 88 deals with presumption as to the existence of a fact, Section 85 deals with presumption as to the regularity of public acts, and Section 70 deals with presumption as to the continuance of a state of things.