Which one of the following agreements is induced by undue influence?

A. A applies to a banker for loan at a time when there is stringency in the money market. The banker declines to make the loan except at an unusually high rate of interest. A accepts the loan on these terms

B. A, enfeebled by disease or age, is induced by B's influence over him as his medical attendant, to agree to pay B an unreasonable sum for his professional services

C. A, at the age of sixty-five years, executes a deed of gift in favour of his only grandson gifting him all his properties to the exclusion of his wife, sons and daughters

D. B, a rich man, donates all his properties to a charitable trust leaving nothing for himself and his family members

Answer: Option B