Which quotation supports the idea that Sir Charles Baskerville had good reason to act and feel the way he did?

"The moor is very sparsely inhabited, and those who live near each other are thrown very much together."

"I whisked round and had just time to catch a glimpse of something which I took to be a large black calf passing at the head of the drive."

"Mr. Stapleton, a mutual friend who was much concerned at his state of health, was of the same opinion."

"On the night of Sir Charles's death Barrymore the butler, who made the discovery, sent Perkins the groom on the horseback to me..."