The correct answer is 2 only.

• Polar Satellite Launch Vehicle (PSLV) is the third generation launch vehicle of India. Hence, Statement 1 is incorrect.
• It is the first Indian launch vehicle to be equipped with liquid stages. Hence, Statement 2 is correct.
• After its first successful launch in October 1994, PSLV emerged as the reliable and versatile workhorse launch vehicle of India with 39 consecutively successful missions by June 2017.
• During the 1994-2017 period, the vehicle has launched 48 Indian satellites and 209 satellites for customers from abroad.
• Besides, the vehicle successfully launched two spacecraft – Chandrayaan-1 in 2008 and Mars Orbiter Spacecraft in 2013 – that later travelled to Moon and Mars respectively.
• PSLV earned its title 'the Workhorse of ISRO' through consistently delivering various satellites to Low Earth Orbits, particularly the IRS series of satellites.
• It can take up to 1,750 kg of payload to Sun-Synchronous Polar Orbits of 600 km altitude.
• Due to its unmatched reliability, PSLV has also been used to launch various satellites into Geosynchronous and Geostationary orbits, like satellites from the IRNSS constellation.
• PSLV uses 6 solid rocket strap-on motors to augment the thrust provided by the first stage in its PSLV-G and PSLV-XL variants.
• However, strap-ons are not used in the core alone version (PSLV-CA).