Which sequence is geometric and has 1/4 as its fifth term and 1/2 as the common ratio?
…, 1, 1/2, 1/4, 1/8, …

…, 1/4, 1/2, 1, 2,…

…, 1/72, 1/36,1/18, 1/9, …

…, 8, 4, 2, 1, …