_ $$\eqalign{ & \frac{1}{{1.2.3}} + \frac{1}{{2.3.4}} + \frac{1}{{3.4.5}} + \frac{1}{{4.5.6}} \cr & {\text{is equal to = ?}} \cr} $$$?

• A. 7/30
• B. 11/30
• C. 13/30
• D. 17/30