Answer:
b. more / does not allow
Step-by-step explanation:
Organisms buried in mud are more likely to be preserved than those buried in sand because mud does not allow oxygen-bearing water to flow through easily.
Oxygen plays a significant role in the decay of organic matter. When organisms die, bacteria and other decomposers break down the organic matter, and oxygen is required for this process.
If oxygen is present, the organic matter will decay rapidly, and little or nothing will be left.
In contrast, mud tends to be more tightly packed than sand, which makes it harder for oxygen to penetrate and circulate, thus reducing the rate of decay and increasing the likelihood of preservation.
Hope this helps!