4. (a) Design a Turing Machine that recognises a binary string in which the number of zeros and ones is the same, i.e. will accept strings 00110011, 010110, 111000 but will reject 011, 100, 000001. (b) Alter you answer to part (a) so that the Turing Machine accepts only strings of a form "1", where n is arbitrary. (c) Explain why it is not possible to design a DFA to recognise the strings of a form 0"1