Answer: d. none of the other answers
Explanation:
Enzymes that turn chemical energy into mechanical work are molecular motors.
There are three main components of cytoskeleton including microtubules, actin filaments and Intermediate filaments. Only actin  filaments and microtubules carry the motor-driven transport on the cytoskeleton.
The most important feature of intermediate filaments is to provide the plasma membrane with mechanical support where it comes into contact with the extracellular matrix and other cells. 
Unlike microtubules and microfilament , intermediate filaments are not involved in motility of the cells, hence do not associat with molecular motors.
Hence, the correct option is d.
 
        
             
        
        
        
I think it'd be B.. I might be wrong tho..
        
                    
             
        
        
        
Water can act as either a base or an acid. Water acts as an acid by donating a hydrogen ion when it reacts with a stronger base such as sodium hydroxide. Water may also act as a base when it accepts hydrogen ion when reacting with a strong acid such as hydrochloric acid. This is based on Bronsted concept and definition of a base ( proton acceptor) and acid (proton donor). Such a  compound that can act as a base and as an acid is called an amphiprotic molecule.
        
             
        
        
        
The answer is B. both need food and air 
        
             
        
        
        
In the small intestine, these cells contain microvilli, which are tiny hair-like projections that increase nutrient absorption. These projections increase the surface area of the small intestine allowing more area for nutrients to be absorbed.