Which is a compound sentence using a subordinating conjunction?

Most Brazilians speak Portuguese; many of their customs are Indian or African.

Most Brazilians speak Portuguese, but many of their customs are Indian or African.

Most Brazilians speak Portuguese, although many of their customs are Indian or African.

Most Brazilians, speaking Portuguese, have Indian or African customs.

Question

Which is a compound sentence using a subordinating conjunction?
	
Most Brazilians speak Portuguese; many of their customs are Indian or African.
 	
Most Brazilians speak Portuguese, but many of their customs are Indian or African.
 	
Most Brazilians speak Portuguese, although many of their customs are Indian or African.
 	
Most Brazilians, speaking Portuguese, have Indian or African customs.

littlediva12459 · Answer

@jim_thompson5910
@Roxy.girl

littlediva12459 · Answer

Most Brazilians speak Portuguese, but many of their customs are Indian or African.?

littlediva12459 · Answer

@tshimp0629

ladycielphantomhive · Answer

A subordinating conjunction follows this format: 

"words words words, additional information, words words." 

Which answer would follow this form?

tshimp0629 · Answer

correct

ladycielphantomhive · Answer

Why would their chosen answer be correct?