The correct option is
C indecent
In this sentence we would be choosing a word alternate to the given word, "salacious"
Salacious means having or conveying undue or inappropriate interest in sexual matters
Indecent means not conforming with generally accepted standards of behaviour, especially in relation to sexual matters.
The above two words are synonymous
If we look into the other words,
Rude means offensively impolite or bad-mannered
Distraught means very worried and upset
Poor means lacking sufficient money to live at a standard considered comfortable or normal in a society
Option B is correct