Siliqua fruit occurs in
Brassica campestris
Brassica campestris or mustard has a simple and dehiscent fruit with a superior, bicarpellary, syncarpous, unilocular ovary which gets divided into two by a false septum known as replum. This kind of fruit is known as siliqua.
Hibiscsus rosa-sinensis has an accessory fruit developing from the thalamus.
Solanum nigram has a simple , dehiscent fruit known as legume.
Althaea rosea has carcerulas type of fruit. So, the correct answer is 'Brassica campestris'