Answer:
Bigfella Conglomerate Inc.
Capital rationing:
To select projects subject to a budget constraint of 5 million dollars, the set of projects that should be accepted in order to maximize firm value are:
Projects 1 and 4.  These projects yielded the highest annual returns and NPV, and the combination could survive under the budget constraint.
Explanation:
a) Data and Calculations:
Project      Initial
Outlay      IRR           NPV             Expected Annual Returns
    1               2 million       18%       2,500,000      $360,000 (18% * $2 million)
   2              1 million         15%         950,000       $150,000 (15% * $1 million)
   3               1 million         10%         600,000       $100,000 (10% * $1 million)
  4              3 million          9%      2,000,000     $270,000 (9% * $3 million)
b) Based on a budget constraint of $5 million, the set of projects that should be accepted to maximize firm value is:
Project      Initial
Outlay      IRR           NPV             Expected Annual Returns
  1               2 million        18%       2,500,000      $360,000 (18% * $2 million)
  4              3 million          9%      2,000,000     $270,000 (9% * $3 million)
Total         5 million                      4,500,000     $630,000
c) In terms of the net present value of cash inflows versus cash outflows, projects 1 and 4 perform far better than projects 2 and 3 combined with project 4.  The expected annual returns based on the Internal Rate of Return (IRR) also indicate that the combination of projects 1 and 4 outperform any other combination of projects.