Myotonic dystrophy is which type of trait?

The pedigree chart below shows the inheritance of a particular sex-linked trait. How is the trait being studied in the pedigree chart above inherited?

Which of the following conditions is harmful in itself but also provides protection against a mosquito-borne infectious disease?

$A$ normal woman,whose father was colour blind,marries a normal man. What is the chance of occurrence of colour blindness in the progeny (in $;\%$)?

Assertion : Persons suffering from haemophilia fail to produce blood clotting factor $VIII$.
Reason : Prothrombin producing platelets in such persons are found in very low concentration.

Which of the following diseases in humans belongs to the same category as hemophilia?