Answer:
 a. not able to be determined from the provided information.
Step-by-step explanation:
For determining the over applied or under applied, first, we have to compute the predetermined rate based on the direct material cost which is 
= $700,000 ÷ $1,000,000 
= $0.70 
Now the applied overhead is 
= $0.70 × $1,200,000 
= $840,000 
And, the actual overhead amount is not given by which we can find out the underapplied or overapplied overhead amount 
So, in this case, the correct option is a.