ANS:D - 27

The figure may be labelled as shown. The simplest squares are EFRQ, MQYX, QRZY, RNSZ, LXWK, XYA₁W, YZB₁A₁, ZSTB₁, SGHT, WA₁VP, A₁B₁UV, B₁TOU and VUIJ i.e. 13 in number. The squares having two components each are AEYL, FBGZ, KA₁JD and B₁HCI i.e. 4 in number. The squares having four components each are MRB₁W, QNTA₁ XZUP and YSOV i.e. 4 in number. The squares having seven components each are AFB₁K, EBHA₁ LZID and YGCJ i.e. 4 in number. There is only one square i.e. MNOP composed of nine components. There is only one square i.e. ABCD composed of seventeen components. There are 13+ 4 + 4 + 4+1 + 1 = 27 squares in the figure.