The probability wave is required to describe an electron's location so that the electron may be found at various distances from the nucleus.
Option c
Step-by-step explanation:
In quantum mechanics, the physical state of an electron can be described by its "wave function".
The standard probability interpretation states that the wave function of an electron is the probability amplitude and its modulus square which gives the probability density of finding an electron in a definite position in space.
The modulus square of the wave function not only gives us the probability density of the atom but it also tells about the possibility of finding an electron at the specific place. It gives us an idea about the distance of an electron from its nucleus. Hence, the probability wave is required to describe an "electron's location".