Final answer:
The magnitude of the unit vector ć is 1, which means it has a length of one unit along the y-axis.
Step-by-step explanation:
The magnitude of a vector indicates its length or size irrespective of its direction. In the case of unit vectors, the magnitude is always equal to 1. This is because unit vectors are defined to have a length of one unit and are used to represent direction along their respective axes. For the unit vector ć, which points along the y-axis, its magnitude is also 1. Therefore, in reference to the options provided in the question, the magnitude of vector ć is 1.