Select the phrase/connector from the given three options which can be used to form a single sentence from the two sentences given below, implying the same as expressed in the statement sentences.
Most processes are more complex than the flying-ball governor. They still obey the same laws of physics that are described by differential equations.
1. certainly
2. although
3. due to
1
Only 1
2
Only 2
3
Only 3
4
Both 1 and 2
5
Both 2 and 3