The major shortcoming of the waterfall model is

Explanation

The waterfall model freezes the requirements in a signed-off SRS before design begins and then flows strictly downwards, so a requirement that changes later forces rework through every completed phase — this rigidity is its classic criticism, and it is why iterative and agile models were introduced. Option 2 is wrong because feasibility analysis comes before requirement analysis, and at that early point changes are still cheap; the pain begins once requirements are baselined. System testing and maintenance are ordinary phases present in every life-cycle model and are not shortcomings peculiar to waterfall. Hence option 1.