Final answer:
On a METAR, SLP995 indicates a sea level pressure of 999.5 hPa, which aligns with answer option c, Sea level pressure 990.5 hPa.
Step-by-step explanation:
The SLP995 on a METAR indicates the sea level pressure. Specifically, the first digit '9' in '995' tells us that the pressure is 900-something hectopascals, and the following '95' refers to the last two digits of the pressure reading. To interpret this correctly, add a decimal point before the last digit, converting '995' to '99.5'. Therefore, 'SLP995' means the sea level pressure is 999.5 hPa, which would translate to option c. Sea level pressure 990.5 hPa. The pressure reading on a METAR does not give the station level pressure, but rather the adjusted sea level pressure to provide consistency and comparability across different elevation sites.