John, who turned 70 years old on October 21, 2020, and has been in good health for the past several years, signed a durable power of attorney in 2015 which grants his brother, Thomas, the power to manage all his real estate rental properties, and to make medical decisions on John's behalf. Thomas has been using this durable power of attorney to assist his brother for the past three years. On the morning of December 7, 2020, John has a massive stroke which leaves him without his mental faculties and unable to understand words spoken to him and to recognize his loved ones. Which of the following is true?

a. The power of attorney contract is terminated by operation of law due to John's lack of capacity to understand the nature and consequences of his actions.

b. The power of attorney contract is not terminated, but merely suspended until such time as John regains his contractual capacity.

c. The power of attorney contract is not impacted by John's lack of capacity such that Thomas may continue to act on John's behalf.

d. The power of attorney contract is not terminated, but John has the duty to inform any third parties of John's current lack of capacity.