Many people had seen the tiger before it disappeared in the jungle.a.Complexb.Simplec.Complex Compoundd.Compound

The given sentence is: "Many people had seen the tiger before it disappeared in the jungle."

To determine the sentence structure, we need to analyze the components and their relationships.

Step 1: Identify the main clause. The main clause in this sentence is "Many people had seen the tiger."

Step 2: Identify any subordinate clauses. There is one subordinate clause in this sentence: "before it disappeared in the jungle."

Step 3: Determine the sentence structure. Based on the analysis, the sentence structure is complex because it contains one main clause and one subordinate clause.

Therefore, the correct answer is: c. Complex.