For phosphofructokinase1 Low ATP stimulates the enzyme but f
     For phosphofructokinase-1:  Low ATP stimulates the enzyme, but fructose-2.6-bisphosphate  inhibits  High ATP stimulates the enzyme, and fructose- 2.6-bisphosphate activates  High ATP stimulates the enzyme, but fructose-2.6-bisphosphate inhibits  Low ATP stimulates the enzyme, and fructose- 2.6-bisphosphate activates  ATP and fructose-2, 6-bisphosphate both inhibit the enzyme 
  
  Solution
Answer is D-Low ATP stimulate the enzyme and fructose-2 6 bis phosphate activates
Phosphofructokinase is a key enzyme to control glycolysis process.It is an allosteric enzyme which is allosterically inhibited by high level of ATP because ATP decrease the enzymes affinity to fructose 6 phosphate.
Fructose 2 6 bisphosphate is a allosteric modular enzyme that activates the enzyme allosterically by increasing its affinity to its substrate fructose 6 phosphate while decreasing it\'s affinity to inhibitory substance (ATP and citrate)

