Answer is 3
c = 0xdeadbeef
can be written as c = 11011110101011011011111011101111
1) c = 0xdeadbeec as c = c = 11011110101011011011111011101100 is true
2) c &= 0xfffffffc as c = 11011110101011011011111011101111&11111111111111111111111111111100 = 11011110101011011011111011101100 = 0xdeadbeec true
3) c = (c >> 2) << 2 now first right shift 2
so c becomes c = 11110111101010110110111110111011 again 2 left shit now c becomes 11011110101011011011111011101100 =0xdeadbeec true
4) c |= 0xfffffffc gives
c = 0xffffffff not true
5) c |= 0x00000003 gives
c = 0xdeadbeef not true