Final answer:
A patient with interstitial lung disease and hypoxemia due to a diffusion defect would typically have fine bibasilar crackles and clubbing of the fingernail beds, indicating options 1 and 2 are correct.
Step-by-step explanation:
A patient with interstitial lung disease who presents with hypoxemia due to a diffusion defect would typically have clinical signs such as fine bibasilar crackles and clubbing of the fingernail beds. Additionally, there might be other signs that indicate a chronic hypoxic state; however, jugular venous distention and an increased P2 heart sound are more indicative of heart issues such as right heart failure not primarily related to interstitial lung disease. Therefore, the most appropriate answers given the options would be (a) fine bibasilar crackles, which can be heard as a crackling sound upon auscultation of the lungs, and (b) clubbing of the fingernail beds, which is a sign of long-term hypoxemia. Hence, the correct choice from the provided options would be 1 and 2.