Option B: “bare” refers to the characteristic of being unclothed. It gives the sentence meaning. Then the sentence means that “While we walked down the beach, our feet were without any cover. Hence, this is the correct option.
Option A: “bear” refers to the act of carrying. This is meaningless in the given case. Hence, this option is incorrect.
Option C: “bore” refers to the act of digging. This is meaningless in the given case. Hence, this option is incorrect.
Option D: “beer” is a beverage. This is meaningless in the given case. Hence, this option is incorrect.