Can anyone answer 4?

Dear Student, a) Father is the colour blind while the mother is the carrier.
b) 3 daughters and 2 sons as daughter is represented by circle and sons by square.
c) Child 1 indicate that this trait is transferred from father to the daughter. 
d) Gene of colourblindness is located on the X chromosome. It is a sex-linked syndrome.
e) Haemophilia is another example of a similar pattern of inheritance.
Regards.