The correct answer is option 3- DistrustIn the given word problem, we have to find the link between the first and the second words in each set. When we look at 'Do' and 'Undo', it becomes easy for us to understand that we need to find the antonym of the word trust.Trust: believe in the reliability, truth, or ability ofDistrust: doubt the honesty or reliability of; regard with suspicionThus we can see that the antonym of trust is distrust.The meaning of the other words-Entrust: assign the responsibility for doing something to (someone)Intrust: it means the same as 'entrust' (archaic and obsolete usage)Untrust: it means the same as 'distrust' (archaic and obsolete usage)