For a general substance $A$ the phase diagram is represented as shown. Identify the option(s) which is/are correct :

Melting point of the substance will increase with increase in pressure.

Triple point of the substance is ($200 K$ and $3.8 mm$ of $Hg$) 

Standard boiling point of the substance should be slightly less than $400K$. 

Above $500K$, gas - liquid transition can not occur without change in temperature.