Final Answer:
The Compliance is not a source of sample attrition, thus the correct option is d.
Step-by-step explanation:
Sample attrition refers to the reduction or loss of participants in a study or sample over time. Inaccessibility, inability, refusal, and compliance are common sources of sample attrition. Inaccessibility occurs when participants become unreachable due to factors such as relocation or changes in contact information. Inability refers to participants' inability to continue participation due to various reasons like health issues or scheduling conflicts. Refusal happens when participants choose not to participate or withdraw from the study voluntarily (option d).
However, compliance is not a source of sample attrition but rather denotes the adherence or agreement of participants to the study protocols and requirements. Compliance is related to the participants' adherence to the study guidelines and instructions, ensuring they follow the study procedures. While compliance is a crucial aspect of maintaining data integrity and reliability, it does not contribute to sample attrition. Instead, compliance supports the study's validity by ensuring participants adhere to the study's protocols, helping to maintain the sample size and data quality throughout the research process. Therefore, among the given options, compliance stands out as the factor that does not contribute to sample attrition, as it relates more to participants' adherence to study guidelines rather than their withdrawal or reduction from the study sample.