Which of the following statements about IAS $2$ Inventories are correct? $1$ Production overheads should be included in cost on the basis of a company's actual level of activity in the period. $2$ In arriving at the net realizable value of inventories, settlement discounts must be deducted from the expected selling price. $3$ In arriving at the cost of inventories, FIFO, LIFO and weighted average cost formulas are acceptable. $4$ It is permitted to value finished goods inventories at materials plus Labour cost only, without adding production overheads.

A $1$

only

B $1$ and $2$

C $3$ and $4$

D None of them