Answer: B. Blood dripping from the murder weapon.
Explanation: In bloodstain pattern analysis, blood spatters behave in accordance with some scientific laws in relation to what caused the bloodshed, the position of the victim and the perpetrators, and the velocity at which the blood is spattered. Since the blood trail is leading away from the stabbed victim, the blood trail is most likely created by the dripping of blood from the murder weapon
 
        
             
        
        
        
Fingerprints that are NOT readily visible are called Latent prints .....
- Latent prints can be found on a variety of surfaces; however, they are not readily visible and detection often requires the use of fingerprint powders, chemical reagents or alternate light sources