Which of the following represents a geometric sequence? I 1 fourth comma 1 fourth comma 1 fourth comma 1 fourth comma dot dot dot II 1 fourth comma 1 fifth comma 1 sixth comma 1 seventh comma dot dot dot III 1 fourth comma 1 comma negative 4 comma 16 comma dot dot dot IV 1 fourth comma negative 4 comma 1 fourth comma negative 4 comma dot dot dot