For adsorption of a gas on a solid, considering the dependence of equilibrium pressure on temperature at constant coverage, which statements are correct?

1. AThe pressure required to maintain a given coverage rises when the temperature is raised
2. BA plot of $\ln p$ against $1/T$ at constant coverage has a negative slope when adsorption is exothermic
3. CThe more negative $\Delta H_{ads}$ is, the more steeply $\ln p$ at constant coverage changes with $1/T$
4. DThe Langmuir constant $K$ of an exothermic adsorption increases as temperature rises