What is the value of $$\tan 10^{\circ} \tan 80^{\circ} + \tan 20^{\circ} \tan 70^{\circ} + \tan 30^{\circ} \tan 60^{\circ} + \tan 40^{\circ} \tan 50^{\circ})$$?

A

4

B

3

C

5

D

2