Amy wants to measure the thickness of a single sheet of A4 size paper. She used a ruler to measure the thickness of a ream of paper with 100 sheets as shown in the figure. Section of ruler is shown next to a ream of paper. The markings on the ruler are from zero to two centimeters. There are two small markings, one is between zero and one and the other is between one and two. The thickness of the ream of paper starts at zero and goes to the small marking which is exactly between zero and one.

Which of these is the most accurate thickness of a single sheet of paper?

0.001 cm
0.005 cm
0.01 cm
0.05 cm