Which of the following are consequences of using ideal standards?

$(1)$ Variance analysis is likely to produce adverse results

$(2)$ Demotivation of staff usually becomes a problem

$(3)$ Allowances for normal efficiency levels are made

$(4)$ Standards can become more useful for long$-$term targets

$1,2$ and $4$

$1$ and $2$ only

$3$ and $4$

$1,2$ and $3$