Which approach is the most cost effective solution for this problem?

Refer to the exhibit. A network administrator needs to add a new VLAN, named VLAN3, to the network shown. Unfortunately, there is not another FastEthernet interface on R1 to connect to the new VLAN3.

Which approach is the most cost effective solution for this problem?

A.
Purchase a new FastEthernet module and install it on R1

B.
Replace R1 with a new router that has at least three FastEthernet interfaces.

C.
Configure a second switch to support VLAN3 with a VLAN trunk between SW1 and the new switch.

D.
Configure a single VLAN trunk between R1 and SW1 and configure subinterface on R1 interface for each VLAN.

E.
Connect another router to a serial interface of R1. Use a FastEthernet interface on the new router for VLAN3.