US National Research Council report on Algal Biofuel (2012) observed that 1. algae and cyanobacteria biomass production in the U.S. desert Southwest could be perceived as a good use of low-value land by some, but as an intrusion into pristine land by others. Similarly, the use of genetically modified organisms in production systems could affect social acceptability. So this is social concern. [and it also proves statement #1 wrong. 2. Open Algal ponds will attract insect larvae invasion and affect predator-prey balance. This is ecological concern. Hence Statement 3 is right. 3. And the report discussed challenges production and technology. Hence answer 2 and 3 .