Consider the following activities in a building construction:
1. Concreting of roof slabs
2. Brick-jelly lime concrete terracing
3. Erection of form work for slab
4. Construction of parapet wall in terrace
The correct sequence of these activities is

A. 9 days B. 13 days C. 14 days D. 19 days

A. $$\frac{{{{\text{t}}_{\text{o}}} + 3{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{2}$$ B. $$\frac{{{{\text{t}}_{\text{o}}} + 3{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{3}$$ C. $$\frac{{{{\text{t}}_{\text{o}}} + 4{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{4}$$ D. $$\frac{{{{\text{t}}_{\text{o}}} + 4{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{5}$$ E. $$\frac{{{{\text{t}}_{\text{o}}} + 4{{\text{t}}_{\text{m}}} + {{\text{t}}_{\text{p}}}}}{6}$$

A. Number of operations B. Output of labour C. Output of machinery D. All the above

A. 3.5 and $$\frac{5}{6}$$ B. 5 and $$\frac{{25}}{{36}}$$ C. 3.5 and $$\frac{{25}}{{36}}$$ D. 4 and $$\frac{5}{6}$$