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 sentence.
Infectious diseases are often public health concerns. They can spread quickly and easily.
1. As far as they
2. When infectious diseases
3. Because they can
1
Only 1
2
Only 2
3
Only 3
4
Both 1 and 3
5
Both 2 and 3