A. is your correct answer
The basic structure of bones is bone matrix, which makes up the underlying rigid framework of bones, composed of both compact bone and spongy bone. The bone matrix consists of tough protein fibers, mainly collagen, that become hard and rigid due to mineralization with calcium crystals.
Scientists find most deep-ocean trenches in the Pacific. Example being the Mariana Trench.
<span>The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition.</span><span>Fossil layers are fossils that formed in sedimentary rock. Sedimentary rock is rock that is formed in layers by the depositing and pressing of sediments on top of each other. </span>
