Gerta finds a sedimentary rock with large clasts cemented together. each clast is larger than 2 mm. gerta has found

a.) sandstone
b.) an evaporite
c.) limestone
d.) a conglomerate

Gerta has found D). A CONGLOMERATE

Clast refers to grains of sedimetnts from minerals or pre-existing rocks. Clastic rocks can range from microscopic to extra large rocks. Sedimentary rocks that have large clast are called phenoclasts. There are only two types of sedimentary rock that has this. These are conglomerate and breccia. Since conglomerate is the only available option,  it is my answer. 

Resistance than a bicycle? i'm not entirely sure