4 (a)

Current price variable (Pa) in BSOP formula 1
Other variables in BSOP formula 1
Calculation of d1 and d2 3
Determination of N(d1) and N(d2) 2
Value of the option to expand decision 1
Revised value of projects and comments Max 3
Assumptions Max 3
Other factors Max 3
––––
Max 16