Four Naval Systems were recently handed over to the Indian Navy by the Defence Minister Manohar Parrikar. With reference to it, which of the following statements is correct?

• A. These naval systems have been designed and developed by Naval Physical and Oceanographic Laboratory (NPOL)
• B. Four Naval Systems are, namely ABHAY, HUMSA UG, NACS and AIDSS
• C. HUMSA-UG is a near-field Acoustic Characterisation System while NACS is an upgrade for the HUMSA SONAR System
• D. All of these