Which one of the following techniques can be used to establish the paternity of a child ?

The standard and most conclusive technique for establishing paternity is DNA fingerprinting (DNA profiling). Modern paternity tests compare specific genetic markers—using methods such as PCR, STR analysis and RFLP—to match the child’s and alleged father’s profiles and thus determine biological relatedness with very high certainty [1]. DNA fingerprinting, developed for forensic and family testing, has largely superseded older protein- and blood-type methods because it directly compares inherited DNA markers and can both exclude non-fathers and include likely fathers with probabilities typically >99.9% when sufficient loci are tested [3]. Techniques like chromosome counting or mere quantitative DNA measurement do not provide the locus-specific matching required for reliable paternity determination.

Sources

1. [1] https://www.jofamericanscience.org/journals/am-sci/0204/12-0205-mahongbao-am.pdf
2. [2] http://www.nature.com/scitable/topicpage/paternity-testing-blood-types-and-dna-374
3. [3] https://www.genetics.edu.au/PDF/Forensic_Paternity_And_Ancestry_Testing_fact_sheet-CGE.pdf