The correct answer is: Blasphemy.
Blasphemy is the act of speaking sacrilegiously about God or a holy person or thing. It is often considered to be a form of religious intolerance or disrespect.
Obscenity is the use of offensive language or behavior. It is often considered to be a form of vulgarity or indecency.
Rudeness is the lack of courtesy or consideration for others. It is often considered to be a form of impoliteness or bad manners.
Vulgarity is the use of coarse or offensive language or behavior. It is often considered to be a form of bad taste or indecency.
In the context of the question, the only option that is a form of disrespect for something sacred or holy is blasphemy. The other options are all forms of disrespect for other people, but they are not specifically related to something sacred or holy.