Which transaction can make a decrease in the Debt-Equity Ratio and an increase in the Current Ratio?

Issue of Equity shares for cash.

Issue of Equity shares increases equity in debt-equity ratio which makes it decrease because debt-equity formula is debt/equity, only equity is increased which makes this ratio to decrease.
Cash increases in current assets on the issue of shares which makes the current ratio increase because only current assets is increased, no effect on current liabilities.