With no explanation, label text_A→text_B with either "DON'T KNOW", "NO" or "YES".
text_A: An audiotape allegedly featuring the voice of bin Laden surfaced on the Internet and addresses the flooding in Pakistan. The 11-minute tape, posted on militant websites Friday, focused on relief efforts and what can be done to prevent future natural disasters. In the recording, bin Laden reportedly urges a change in how governments execute relief work and calls for the creation of a relief group to study Muslim regions located near rivers and low-lying areas. He also calls for a greater investment in agriculture. The U.S.-based SITE Intelligence Group, which monitors jihadi forums, says the latest message is heard in a video featuring a photograph of bin Laden superimposed over images of aid distribution.
text_B: Is it likely that relief groups tightened their security after the Bin Laden video surfaced online?
DON'T KNOW.