Could you please explain and prove why such choices are right?

4.1 Bike AG is a Swiss bicycle retailer. In 2018, the following events occur. Evaluate them in terms of their effect on income or liquidity (Bike AG prepares its income statement according to the costs of goods sold method). Tick exactly one box per event. (6 points) a) Bike AG buys bicycles for a total of CHF 150,000 on account. affecting liquidity affecting income affecting both I no effect b) Bike AG pays the invoice and transfers CHF 150'000 to the supplier. affecting liquidity affecting income affecting both I no effect c) Bike AG sells bicycles on account for CHF 200'0000 to a customer. affecting liquidity affecting income affecting both O no effect d) Bike AG sells bicycles for CHF 200'0000 to a customer. The customer pays in cash. affecting liquidity affecting income affecting both no effect