In order to bring all 10 coins with Tails (T) face as the upper face, we need to turn each coin exactly once.

In each attempt, we can turn exactly four coins.

Therefore, we need to find the minimum number of attempts required to turn all 10 coins.

Let`s consider the options:

Option 1: 4 attempts

In this option, we can turn four coins in each attempt. After the first attempt, four coins will have T as the upper face. In the second attempt, we can turn the remaining six coins to bring all coins with T as the upper face. So, in total, it takes only 2 attempts to complete the task.

Option 2: 5 attempts

In this option, even if we turn four coins in each attempt, it will take 5 attempts to turn all 10 coins. This contradicts the requirement of the minimum number of attempts, so option 2 is not the correct answer.

Option 3: 6 attempts

Similarly, in this option, it will take 6 attempts to turn all 10 coins. This contradicts the requirement of the minimum number of attempts, so option 3 is not the correct answer.

Option 4: 7 attempts