Explanation:

Slowing economic growth will mean lower GDP growth, For the tax/GDP ratio to decrease either the tax collection should decrease or GDP should increase. So, a decrease in tax to GDP ratio may not directly indicate slowing economic growth rate.

Now considering the first statement if the GDP collection might or might not necessarily increase with a slow growth rate. Hence this option is ruled out. Increase in indirect tax collection may lead to less equality in income distribution but the same cannot be said for increase in direct tax collection. Hence, even this option can be ruled out.