The missile named 'Nag' developed by DRDO is a/an:

Consider the following statements regarding ballistic missile systems: I. Solid-fuel ballistic missiles generally permit faster launch readiness compared to liquid-fuel missile systems. II. Medium-range ballistic missiles (MRBMs) are typically capable of striking targets beyond the immediate tactical battlefield but below intercontinental ranges. III. Road-mobile missile platforms enhance survivability by improving mobility and reducing vulnerability to pre-emptive strikes. IV. Hypersonic speed necessarily implies that a missile can completely evade all existing air and missile defence systems. Which of the statements given above are correct?

With reference to the Naval Anti-ship Missile–Short Range (NASM-SR), consider the following statements: I. It is an air-launched missile system intended primarily for deployment from naval helicopter platforms. II. A sea-skimming flight profile helps anti-ship missiles reduce the probability of radar detection during terminal approach. III. The 'lock-on-after-launch' capability enables a missile to acquire or update its target after being launched. IV. Solid-fuel propulsion systems used in tactical missiles necessarily require atmospheric oxygen for combustion during flight. How many of the statements given above are correct?