Tangeni has invested in mining exploration for several years but has not yet begun production. When he finally starts generating income from the mine, how should he handle the exploration costs incurred prior to production?

O a$.$ The exploratiort costs can only be deducted once mining production ceases.

$$ b$.$ He must spread the deduction of exploration costs over $4$ years.

$$ c$.$ He can only deduct $50\%$ of the exploration costs in the first year.

Od$.$ He can deduct all exploration costs in the first year of income generation.