<span>A hero is known as someone with admirable
characteristics, brave personality and for most of us, a hero is someone who
has super powers. We can all be heroes it’s just that we need to discover it
within us. Being a hero does not mean you need to have super powers. You can be
a hero to yourself, to someone, to everyone by just showing kindness, spreading
love and doing things that can influence people in a good way. The hero within
you is just being you. </span>
I'd say the answer is 'the visible is more dangerous than the invisible', because Duncan never suspected that his faithful Macbeth would be the one to kill him.
Apparently this included "inappropriate." words or phrases, so I took screenshots of what I had typed, hope it helps.
One of the answers that could fit in the blank is better.
Hope this clarifies your doubt.
