Which sentence uses a euphemism to show sensitivity over the death of a pet?

Question

I heard that you had to dispose of your dog last week.

I heard that you euthanized your dog last week.

I heard that your dog was put down last week.

I heard that you had to put your dog to sleep last week.

Answer 1

The sentence that uses a euphemism to show sensitivity over the death of a pet is: "I heard that you had to put your dog to sleep last week."