Which of these are unit vectors
Option a has just ^i so it's understood that it has magnitude 1 in x direction.
Option b is ^i+^j+^k. Magnitude is found by √
So we have magnitude as √=√so wrong.
Option c is ^i√+^j√ so ,magnitude is √=1so correct
Option d is 45^i+35^j so ,magnitude is √=1so correct